The present invention relates generally to medical devices and in particular aspects to medical products and methods for treating fistulae.
As further background, a variety of fistulae can occur in humans. These fistulae can occur for a variety of reasons, such as but not limited to, as a congenital defect, as a result of inflammatory bowel disease, such as Chron's disease, irradiation, trauma, such as childbirth, or as a side effect from a surgical procedure. Further, several different types of fistulae can occur, for example, urethro-vaginal fistulae, vesico-vaginal fistulae, tracheo-esophageal fistulae, gastrointestinal fistulae, and any number of anorectal fistulae, such as recto-vaginal fistula, recto-vesical fistulae, recto-urethral fistulae, or recto-prostatic fistulae.
A gastrointestinal fistula is an abnormal passage that leaks the contents of the stomach or the intestine (small or large bowel) to other organs, usually other parts of the intestine or the skin. For example, gastrojejunocolic fistulae include both enterocutaneous fistulae (those occurring between the intestine, namely the duodenum, or the jejunum, or the ileum, and the skin surface) and gastric fistulae (those occurring between the stomach and skin surface). Another type of fistulae occurring in the gastrointestinal tract is an enteroenteral fistula, which refers to fistulae occurring between two parts of the intestine. Gastrointestinal fistulae can result in malnutrition and dehydration depending on their location in the gastrointestinal tract. They can also be a source of skin problems and infection. The majority of these types of fistulae are the result of surgery (e.g., bowel surgery), although sometimes they can develop spontaneously or from trauma, especially penetrating traumas such as stab wounds or gunshot wounds. Inflammatory processes, such as infection or inflammatory bowel disease (Crohn's disease), may also cause gastrointestinal fistulae. In fact, Crohn's disease is the most common primary bowel disease leading to enterocutaneous fistulae, and surgical treatment may be difficult because additional enterocutaneous fistulae can develop in many of these patients postoperatively.
The path which these fistulae take, and their complexity, can vary. A fistula may take a “straight line” path from the primary to the secondary opening, known as a simple fistula. Alternatively, the fistula may consist of multiple tracts ramifying from the primary opening and have multiple secondary openings. This is known as a complex fistula.
Treatment options for gastrointestinal fistulae vary from patient to patient. Depending on the clinical situation, patients may require IV nutrition and a period of time without food to allow the fistula time to close on its own. Indeed, nonsurgical therapy may allow spontaneous closure of the fistula, though this can be expected less than 30% of the time. A variable amount of time to allow spontaneous closure of fistulas has been recommended, ranging from 30 days to 6 to 8 weeks. During this time, external control of the fistula drainage prevents skin disruption and may provide a guideline for fluid and electrolyte replacement. In some cases, surgery is necessary to remove the segment of intestine involved in a non-healing fistula.
When surgery is deemed necessary, the preferred operation for fistula closure is resection of the fistula-bearing segment and primary end-to-end anastamosis. The anastomosis may be reinforced by greater omentum or a serosal patch from adjacent small bowel. Still other methods for treating fistulae involve injecting sclerosant or sealant (e.g., collagen or fibrin glue) into the tract of the fistula to block the fistula. Closure of a fistula using a sealant is typically performed as a two-stage procedure, including a first-stage seton placement and injection of the fibrin glue several weeks later. This allows residual infection to resolve and to allow the fistula tract to “mature” prior to injecting a sealant. If sealant or sclerosant were injected as a one-stage procedure, into an “unprepared” or infected fistula, this may cause a flare-up of the infection and even further abscess formation.
There remain needs for improved and/or alternative medical products, methods, and systems that are useful for treating fistulae, particularly gastrointestinal fistulae. The present invention is addressed to those needs.